Easton's Bible Dictionary (1897)/Holy of holies
Appearance
Holy of holies: the second or interior portion of the tabernacle. It was left in total darkness. No one was permitted to enter it except the high priest, and that only once a year. It contained the ark of the covenant only (Exodus 25:10-16). It was in the form of a perfect cube of 20 cubits. (See TABERNACLE.)